Processors in computers employ variable power-performance states to match operating states to processor load. Modern processors incorporate dynamic voltage and frequency scaling as integral mechanisms to tailor operating states. These operating state changes are typically managed by the operating system or system firmware using explicit, special instructions to cause processor operating state change. Management of these states by the system software layer is typically designed to take a conservative approach, and therefore limits the benefits that can be extracted using the state change mechanisms.
Further, management systems and methods historically have utilized a single operational point to select performance at a given time instant. This traditional scheme, however, inhibits degrees of freedom that may exist in the underlying system where it may be possible to vary operational points in a much faster manner to track very short time interval behavior that is unseen and unmanageable by the higher levels of the system. System software is typically unaware of the fine-grain variations in workload characteristics that rapidly alter the performance-level required from the hardware.